1. Field of the Invention
The present invention relates to an inspecting technology for a display panel, and particularly to an inspecting circuit layout for a liquid crystal display (LCD) panel and a fabricating method for such an LCD panel.
2. Description of Related Art
The fast development of multi-media technology can be attributed to the progress in semiconductor components and display devices. As to display devices, LCDs, with such advantages as high pixel quality, good spatial utilization, low power consumption and no radiation, have become a mainstream product in the display market.
FIG. 1 is an exploded schematic view of a conventional active matrix (AM) LCD panel. Referring to FIG. 1, the AM-LCD panel 100 includes an active element array substrate 110, a liquid crystal layer 120 and a color filter 130. The color filter 130 is disposed over the active element array substrate 110. The liquid crystal layer 120 is disposed between the active element array substrate 110 and the color filter 130. The active element array substrate 110 has a plurality of active elements 112 distributed as an array thereon, and a plurality of pixel electrodes 114. Each active element 112 corresponds to a given pixel electrode 114, the active element 112 serving as a switch for a pixel unit. In order to drive active elements 112 of a given pixel unit, a scan line 116 and a data line 118 are typically used for selecting the given pixel unit and providing an appropriate voltage to display a corresponding frame.
FIG. 2 is a schematic view of a conventional inspecting circuit layout for panel units. Referring to FIG. 2, the AM-LCD panel 100 of FIG. 1 is fabricated by a process including: assembling a large area of active element array substrate with a large area of color filter for enclosing a liquid crystal layer therebetween, therefore a plurality of panel units 200 distributed as an array is formed; and then performing a cutting process to form a plurality of the AM-LCD panels 100 of FIG. 1.
In order to inspect the electric characteristic of the conventional panel units 200, shorting bars 140 are employed for connecting scan lines and data lines of each panel unit 200 with the scan lines and data lines of the other panel units in series, respectively, and each shorting bar 140 being electrically connected to a pad 210. A probe (not shown) is pressed against the pad 210, such that signals can be input to the scan lines of the panel units via the probe, thus triggering the active elements 112 of FIG. 1. Thereafter, inspecting signals are transferred to the data lines of the panel units 200 via the probe. The panel units 200 can display frames according to the inspecting signals. Therefore, operators can identify whether the panel units 200 are qualified or not according to the displayed frames.
For fabricating small-sized display panel, a piece of glass substrate can be made into tens or hundreds of panel units. As shown in FIG. 2, in order to simultaneously inspect the electrical characteristics of the panel units 200, the panel units 200 have to be constantly charged and the probe (not shown) pressed against the pad 210 to transfer the inspecting signals to each of the panel units 200. In other words, during such an inspecting process, all of the active elements (not shown) in the panel units 200 are at ON state. After the all of the panel units are inspected, all of the active elements (not shown) in the panel units 200 are turned to OFF state.
According to the foregoing inspecting methods, only one set of probes pressing against the pad 210 is needed for inspecting all of the panel units 200. However, having maintained an on state for a long time, the active elements are likely to have characteristics variations and may not operate properly.
In solution, another conventional inspecting method is proposed. FIG. 3 is a schematic view of another conventional inspecting circuit layout for panel units. Referring to FIG. 3, the panel units 200 are divided into a plurality of groups, each group panel units being respectively electrically connected to a corresponding pad 300. Consequently, when inspecting the panel units 200, only the group of panel units to be inspected is needed to be charged and the probe (not shown) pressing against the pad 300 transfers the inspecting signals into each of the panel units 200. After the group of panel units is inspected, the active elements of the group of panel units can be turned to OFF state. In other words, such an inspecting method is adapted for shortening the ON-state time of the active elements.
However, the inspecting method can inspect only one group of panel unit in one time. Therefore, after inspecting one group of panel units, the probe has to be moved to another pad corresponding to the next group of panel units, calibrated, to accurately press against the pad. Therefore, more groups of panel units would require for more inspecting time for all of the panel units. Although using more probes may allow more groups of panel units to be inspected at same time and shorten the inspecting time, the corresponding inspecting cost is also increased.